Hose-end sprayers are generally well-known and are described, for example, in U.S. Pat. No. 6,425,534 (issued Jul. 30, 2002), U.S. Pat. No. 5,372,310 (Dec. 3, 1994) and U.S. Pat. No. 5,320,288 (Jun. 14, 1994). These patents provide general background information with regard to hose-end sprayers that may be of use in better understanding the makeup and functioning of various embodiments of the present invention. For instance, these patents provide illustrative and non-restrictive examples of how a carrier stream and chemical product can be selectably mixed and admitted through a sprayer, and how alternatively solely a carrier stream can be admitted.
Generally, a strong and compelling need has been recognized in connection with providing hose-end sprayers and similar arrangements with effective safety features to prevent, at the very least, inadvertent spilling or leaking of chemical product in general and/or access to chemical product by children in particular.